MCP-B

https://docs.mcp-b.ai/
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MCP-B is a browser runtime that combines the WebMCP standard with Model Context Protocol extensions,...
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### Install the SDK

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Use npm to install the package in your project.

```bash
npm install @mcp-b/webmcp-ts-sdk
```

--------------------------------

### Install Package

Source: https://docs.mcp-b.ai/packages/extension-tools/reference

Command to install the extension tools and the MCP SDK.

```bash
npm install @mcp-b/extension-tools @modelcontextprotocol/sdk
```

--------------------------------

### Install usewebmcp package

Source: https://docs.mcp-b.ai/packages/usewebmcp/reference

Install the package and its React dependency using pnpm.

```bash
pnpm add usewebmcp react
```

--------------------------------

### Install @mcp-b/smart-dom-reader

Source: https://docs.mcp-b.ai/packages/smart-dom-reader/reference

Install the package via npm.

```bash
npm install @mcp-b/smart-dom-reader
```

--------------------------------

### Install usewebmcp dependencies

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Install the core library and React peer dependency.

```bash
npm install usewebmcp react
```

--------------------------------

### Install @mcp-b/mcp-iframe

Source: https://docs.mcp-b.ai/packages/mcp-iframe/reference

Install the package and the required MCP SDK dependency.

```bash
pnpm add @mcp-b/mcp-iframe @modelcontextprotocol/sdk
```

--------------------------------

### Start development server

Source: https://docs.mcp-b.ai/tutorials/first-react-tool

Launch the local development server.

```bash
npm run dev
```

--------------------------------

### Scaffold and install dependencies

Source: https://docs.mcp-b.ai/tutorials/first-react-tool

Initialize a new Vite React project and install the required WebMCP packages.

```bash
npm create vite@latest my-webmcp-react -- --template react-ts
cd my-webmcp-react
```

```bash
npm install @mcp-b/webmcp-polyfill usewebmcp
```

--------------------------------

### Install MCP-B Runtime

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Install the full MCP-B runtime package.

```bash
npm install @mcp-b/global
```

--------------------------------

### Instantiate BrowserMcpServer

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Example of initializing the server with basic metadata and native context.

```ts
import { BrowserMcpServer } from '@mcp-b/webmcp-ts-sdk';

const server = new BrowserMcpServer(
  { name: 'my-app', version: '1.0.0' },
  { native: document.modelContext }
);
```

--------------------------------

### Install @mcp-b/global

Source: https://docs.mcp-b.ai/packages/global/reference

Installation methods for the package using npm, pnpm, or direct script tags.

```bash
npm install @mcp-b/global
```

```bash
pnpm add @mcp-b/global
```

```html
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```

```html
<script type="module">
  import '@mcp-b/global';
</script>
```

--------------------------------

### Install WebMCP Polyfill

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Install the polyfill package to enable the WebMCP standard on the document object.

```bash
npm install @mcp-b/webmcp-polyfill
```

--------------------------------

### Install WebMCP Types

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Install type definitions to enable argument inference for tools.

```bash
npm install --save-dev @mcp-b/webmcp-types
```

--------------------------------

### Install react-webmcp dependencies

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Install the core package and Zod peer dependency.

```bash
pnpm add @mcp-b/react-webmcp zod
```

--------------------------------

### Install client functionality dependencies

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Install additional packages required for client-side MCP functionality.

```bash
pnpm add @mcp-b/transports @modelcontextprotocol/sdk
```

--------------------------------

### Install WebMCP Runtime

Source: https://docs.mcp-b.ai/how-to/add-tools-to-an-existing-app

Install the runtime package via npm or include it via a script tag if no build step is present.

```bash
npm install @mcp-b/global
```

```typescript
import '@mcp-b/global';
```

```html
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```

--------------------------------

### Using the test-webmcp-tool prompt

Source: https://docs.mcp-b.ai/how-to/use-devtools-mcp

Example of invoking the built-in test-webmcp-tool prompt with specific arguments.

```text
Use the test-webmcp-tool prompt with toolName=search_products devServerUrl=http://localhost:5173
```

--------------------------------

### CLI Usage Examples

Source: https://docs.mcp-b.ai/packages/webmcp-local-relay/reference

Common command-line patterns for configuring ports, origins, and relay identification.

```bash
# Custom port
npx @mcp-b/webmcp-local-relay --port 9444

# Restrict to trusted origins
npx @mcp-b/webmcp-local-relay --widget-origin https://myapp.com,https://other.com

# Label and identify the relay for multi-relay selection
npx @mcp-b/webmcp-local-relay --label "dev" --workspace "myapp" --relay-id "relay-01"
```

--------------------------------

### initializeWebMCPPolyfill(options?)

Source: https://docs.mcp-b.ai/packages/webmcp-polyfill/reference

Installs the strict core polyfill on document.modelContext. This function is safe to call repeatedly and performs a no-op in non-browser environments.

```APIDOC
## initializeWebMCPPolyfill(options?)

### Description
Installs the strict core polyfill on `document.modelContext`. If `document.modelContext` already exists, initialization is skipped.

### Parameters
- **options** (object) - Optional
  - **autoInitialize** (boolean) - Default: true. Set false to disable auto-init from IIFE/import side effect.
  - **installTestingShim** (boolean | 'always' | 'if-missing') - Default: 'if-missing'. Controls installation of `navigator.modelContextTesting`.
  - **disableIframeTransportByDefault** (boolean) - Deprecated no-op.

### Usage Example
```ts
import { initializeWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';

initializeWebMCPPolyfill();
```
```

--------------------------------

### Install React hooks packages

Source: https://docs.mcp-b.ai/start-here/choose-your-path

Install hooks for full MCP-B runtime support or strict core tool registration.

```bash
# Full MCP-B hooks
npm install @mcp-b/react-webmcp

# Strict core hooks
npm install usewebmcp
```

--------------------------------

### Install @mcp-b/global runtime

Source: https://docs.mcp-b.ai/how-to/frameworks

Install the full WebMCP runtime using npm, pnpm, or a script tag. Note that this package accesses browser APIs on import and requires SSR guards.

```bash
npm install @mcp-b/global
```

```bash
pnpm add @mcp-b/global
```

```html
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```

--------------------------------

### Install @mcp-b/transports

Source: https://docs.mcp-b.ai/packages/transports/reference

Install the package using pnpm. Requires @mcp-b/webmcp-ts-sdk as a peer dependency.

```bash
pnpm add @mcp-b/transports
```

--------------------------------

### Install @mcp-b/react-webmcp dependencies

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Install the full MCP-B React package along with the required global runtime and Zod for schema validation.

```bash
npm install @mcp-b/react-webmcp @mcp-b/global zod
```

--------------------------------

### Declare Extension Permissions

Source: https://docs.mcp-b.ai/packages/extension-tools/reference

Example of declaring required permissions and host permissions in a manifest.json file.

```json
{
  "manifest_version": 3,
  "permissions": ["tabs", "bookmarks", "storage", "scripting"],
  "host_permissions": ["<all_urls>"]
}
```

--------------------------------

### Verify connected WebMCP sources

Source: https://docs.mcp-b.ai/tutorials/desktop-agent-relay

Example output from the webmcp_list_sources tool showing connected browser tabs.

```json
[
  {
    "tabId": "abc123",
    "origin": "file://",
    "url": "file:///path/to/relay-demo.html",
    "title": "Relay Demo Page",
    "toolCount": 1
  }
]
```

--------------------------------

### Verify tools with standard consumer methods

Source: https://docs.mcp-b.ai/how-to/add-tools-to-an-existing-app

Use standard in-page consumer methods to retrieve and execute tools when the global package is installed.

```ts
const tools = await document.modelContext.getTools();
const searchTool = tools.find((tool) => tool.name === 'search-products');
if (!searchTool) throw new Error('search-products is not available');

const resultJson = await document.modelContext.executeTool(
  searchTool,
  JSON.stringify({ query: 'laptop' })
);
const result = resultJson === null ? null : JSON.parse(resultJson);
```

--------------------------------

### Install mcp-iframe dependencies

Source: https://docs.mcp-b.ai/how-to/bridge-tools-across-iframes

Install the required packages for bridging MCP tools across iframe boundaries.

```bash
npm install @mcp-b/mcp-iframe @modelcontextprotocol/sdk
```

--------------------------------

### Initialize the WebMCP polyfill

Source: https://docs.mcp-b.ai/packages/webmcp-polyfill/reference

Installs the strict core polyfill on document.modelContext. It is safe to call repeatedly and is a no-op in non-browser environments.

```ts
import { initializeWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';

initializeWebMCPPolyfill();
```

--------------------------------

### Package Metadata

Source: https://docs.mcp-b.ai/packages/webmcp-local-relay/reference

Basic package information including installation source, license, and Node.js version requirements.

```text
npm: @mcp-b/webmcp-local-relay
license: MIT
node: >= 22
```

--------------------------------

### cleanupWebMCPPolyfill()

Source: https://docs.mcp-b.ai/packages/webmcp-polyfill/reference

Restores previous document.modelContext and navigator.modelContextTesting property descriptors and resets the polyfill install state.

```APIDOC
## cleanupWebMCPPolyfill()

### Description
Restores previous `document.modelContext` and `navigator.modelContextTesting` property descriptors and resets the polyfill install state.

### Usage Example
```ts
import { cleanupWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';

cleanupWebMCPPolyfill();
```
```

--------------------------------

### Install Chrome DevTools MCP

Source: https://docs.mcp-b.ai/packages/chrome-devtools-mcp/overview

Use this command to execute the latest version of the upstream Chrome DevTools MCP server via npx.

```bash
npx -y chrome-devtools-mcp@latest
```

--------------------------------

### Start Chrome with remote debugging enabled

Source: https://docs.mcp-b.ai/how-to/use-devtools-mcp

Launch Chrome with the --remote-debugging-port flag to enable external connections. Ensure the user-data-dir is specified to avoid conflicts with existing sessions.

```bash
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome \
  --remote-debugging-port=9222 \
  --user-data-dir=/tmp/chrome-profile-stable
```

```bash
google-chrome --remote-debugging-port=9222 \
  --user-data-dir=/tmp/chrome-profile-stable
```

```bash
"C:\Program Files\Google\Chrome\Application\chrome.exe" ^
  --remote-debugging-port=9222 ^
  --user-data-dir="%TEMP%\chrome-profile-stable"
```

--------------------------------

### new BrowserMcpServer(serverInfo, options)

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Initializes a new instance of the BrowserMcpServer with the specified server information and configuration options.

```APIDOC
## Constructor: new BrowserMcpServer(serverInfo, options)

### Description
Creates a new BrowserMcpServer instance to handle MCP communication in the browser.

### Parameters
- **serverInfo** (Implementation) - Required - Object containing the server name and version (e.g., { name: string; version: string }).
- **options** (BrowserMcpServerOptions) - Optional - Configuration options including native context, capabilities, and JSON schema validators.

### BrowserMcpServerOptions
- **native** (ModelContextCore) - Optional - Reference to the native/polyfill modelContext.
- **capabilities** (ServerCapabilities) - Optional - Additional MCP capabilities for tools, resources, and prompts.
- **jsonSchemaValidator** (JsonSchemaValidator) - Optional - Custom JSON Schema validator.

### Usage Example
```ts
import { BrowserMcpServer } from '@mcp-b/webmcp-ts-sdk';

const server = new BrowserMcpServer(
  { name: 'my-app', version: '1.0.0' },
  { native: document.modelContext }
);
```
```

--------------------------------

### Initialize in Frontend Frameworks

Source: https://docs.mcp-b.ai/how-to/frameworks

Standard entry point initialization for React, Vue, Svelte, and Angular applications.

```tsx
import '@mcp-b/global';
import { createRoot } from 'react-dom/client';
import { App } from './App';

createRoot(document.getElementById('root')!).render(<App />);
```

```typescript
import '@mcp-b/global';
import { createApp } from 'vue';
import App from './App.vue';

createApp(App).mount('#app');
```

```typescript
import '@mcp-b/global';
import App from './App.svelte';

const app = new App({ target: document.getElementById('app')! });
export default app;
```

```typescript
import '@mcp-b/global';
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app/app.component';

bootstrapApplication(AppComponent);
```

--------------------------------

### Initialize in Astro

Source: https://docs.mcp-b.ai/how-to/frameworks

Import via script tag or load the IIFE directly in the layout head.

```astro
<script>
  import '@mcp-b/global';
</script>
```

```astro
<head>
  <script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
</head>
```

--------------------------------

### Create the relay-demo.html file

Source: https://docs.mcp-b.ai/tutorials/desktop-agent-relay

This HTML file registers a tool and loads the embed script to connect to the local relay. Ensure the embed script is loaded after tool registration.

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Relay Demo Page</title>
    <script src="https://cdn.jsdelivr.net/npm/@mcp-b/global@latest/dist/index.iife.js"></script>
  </head>
  <body>
    <h1>Relay Demo</h1>
    <p id="status">Registering tool...</p>

    <script>
      document.modelContext.registerTool({
        name: 'get_page_title',
        description: 'Get the current page title',
        inputSchema: { type: 'object', properties: {} },
        execute: async () => ({
          content: [{ type: 'text', text: document.title }],
        }),
      });

      document.getElementById('status').textContent =
        'Tool "get_page_title" registered. Waiting for relay connection...';
    </script>

    <script src="https://cdn.jsdelivr.net/npm/@mcp-b/webmcp-local-relay@latest/dist/browser/embed.js"></script>
  </body>
</html>
```

--------------------------------

### Initialize BrowserMcpServer Constructor

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Defines the signature for creating a new BrowserMcpServer instance.

```ts
new BrowserMcpServer(serverInfo: Implementation, options?: BrowserMcpServerOptions)
```

--------------------------------

### Selector Ranking Examples

Source: https://docs.mcp-b.ai/packages/smart-dom-reader/reference

Examples of CSS selectors categorized by their stability score for reliable element identification.

```css
#unique-id
```

```css
[data-testid="submit"]
```

```css
[role="button"][aria-label="Submit"]
```

```css
input[name="email"]
```

```css
.form-container .submit-btn
```

--------------------------------

### initializeWebModelContext(options?)

Source: https://docs.mcp-b.ai/packages/global/reference

Initializes the global adapter and replaces document.modelContext with a BrowserMcpServer instance. This function is idempotent and safe for SSR environments.

```APIDOC
## initializeWebModelContext(options?)

### Description
Initializes the global adapter, replacing `document.modelContext` with a `BrowserMcpServer` instance. It is idempotent and performs a no-op in non-browser environments.

### Parameters
- **options** (object) - Optional - Configuration object for the transport layer, including `tabServer` settings like `allowedOrigins`.
```

--------------------------------

### Discover WebMCP tools

Source: https://docs.mcp-b.ai/how-to/use-devtools-mcp

List tools available on a webpage that has @mcp-b/global installed.

```text
Navigate to https://webmcp.sh and list the available tools
```

--------------------------------

### Initialize HTML for WebMCP

Source: https://docs.mcp-b.ai/tutorials/first-tool

Create the base HTML structure and load the WebMCP polyfill via a script tag.

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>My First WebMCP Tool</title>
    <script src="https://unpkg.com/@mcp-b/webmcp-polyfill@latest/dist/index.iife.js"></script>
  </head>
  <body>
    <h1>My First WebMCP Tool</h1>
    <p id="status">Loading...</p>

    <script>
      // We will register our tool here in the next step.
    </script>
  </body>
</html>
```

--------------------------------

### Get tool descriptors

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Retrieves WebMCP producer tool descriptors for registered tools.

```ts
const tools = await server.getTools();
const searchTool = tools.find((tool) => tool.name === 'search');
if (!searchTool) throw new Error('search is not available');
```

--------------------------------

### CLI Help Output

Source: https://docs.mcp-b.ai/packages/webmcp-local-relay/reference

Displays the available command-line options and flags for the relay.

```text
webmcp-local-relay [options]

  --host, -H               Bind host for local websocket relay (default: 127.0.0.1)
  --port, -p               Preferred root port for the local relay cluster (default: 9333)
  --widget-origin          Allowed host page origin(s), comma-separated (default: *)
  --allowed-origin         Alias for --widget-origin
  --ws-origin              Alias for --widget-origin
  --label                  Human-readable relay label reported during discovery
  --workspace              Optional workspace name reported during discovery
  --relay-id               Stable relay identifier reported during discovery
  --help, -h               Show help
```

--------------------------------

### Complete index.html for WebMCP Tool

Source: https://docs.mcp-b.ai/tutorials/first-tool

A full HTML boilerplate including the WebMCP polyfill and a basic tool registration script.

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>My First WebMCP Tool</title>
    <script src="https://unpkg.com/@mcp-b/webmcp-polyfill@latest/dist/index.iife.js"></script>
  </head>
  <body>
    <h1>My First WebMCP Tool</h1>
    <p id="status">Loading...</p>

    <script>
      document.modelContext.registerTool({
        name: 'get-page-title',
        description: 'Get the current page title',
        inputSchema: { type: 'object', properties: {} },
        async execute() {
          return {
            content: [{ type: 'text', text: document.title }],
          };
        },
      });

      document.getElementById('status').textContent = 'Tool "get-page-title" registered.';
    </script>
  </body>
</html>
```

--------------------------------

### Initialize in Vanilla JS

Source: https://docs.mcp-b.ai/how-to/frameworks

Import via module bundler or include the IIFE script directly in HTML.

```typescript
import '@mcp-b/global';
```

```html
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```

--------------------------------

### Import useWebMCPPrompt hook

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Import the hook for registering MCP prompts.

```ts
import { useWebMCPPrompt } from '@mcp-b/react-webmcp';
```

--------------------------------

### Troubleshoot Common Test Issues

Source: https://docs.mcp-b.ai/how-to/test-native-and-polyfill

Commands to resolve environment conflicts or installation issues during test execution.

```bash
lsof -ti:4173 | xargs kill
```

```bash
pnpm --filter mcp-e2e-tests exec playwright install chromium
```

--------------------------------

### useWebMCPContext(name, description, getValue)

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

A convenience wrapper for creating read-only context tools that automatically set appropriate hints.

```APIDOC
## useWebMCPContext(name, description, getValue)

### Description
Registers a read-only context tool. This is a shorthand for useWebMCP with pre-configured hints (readOnly, idempotent).

### Parameters
- **name** (string) - Required - Tool identifier
- **description** (string) - Required - Description for AI assistants
- **getValue** (function) - Required - Function returning the current context value: () => T
```

--------------------------------

### Get Feedback

Source: https://docs.mcp-b.ai/llms.txt

Retrieves user feedback from your documentation, including page ratings and code snippet feedback.

```APIDOC
## Get Feedback

### Description
Retrieves user feedback from your documentation, including page ratings and code snippet feedback.

### Method
GET

### Endpoint
/api/analytics/feedback

### Parameters
#### Query Parameters
- **start_date** (string) - Optional - The start date for filtering feedback.
- **end_date** (string) - Optional - The end date for filtering feedback.
```

--------------------------------

### Enable experimental browser features via CLI

Source: https://docs.mcp-b.ai/how-to/debug-and-troubleshoot

Launches Chrome with the necessary experimental flags to support native WebMCP features.

```bash
google-chrome --enable-experimental-web-platform-features http://localhost:3000
```

--------------------------------

### Cleanup the WebMCP polyfill

Source: https://docs.mcp-b.ai/packages/webmcp-polyfill/reference

Restores previous document.modelContext and navigator.modelContextTesting property descriptors and resets the polyfill install state.

```ts
import { cleanupWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';

cleanupWebMCPPolyfill();
```

--------------------------------

### Register Chrome Extension Tools

Source: https://docs.mcp-b.ai/packages/extension-tools/reference

Demonstrates how to initialize an McpServer and register specific Chrome API tool classes in a background script.

```typescript
import { TabsApiTools, BookmarksApiTools, StorageApiTools } from '@mcp-b/extension-tools';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';

const server = new McpServer({
  name: 'chrome-extension-server',
  version: '1.0.0',
});

const tabsTools = new TabsApiTools(server, {
  listActiveTabs: true,
  createTab: true,
  closeTabs: true,
});
tabsTools.register();

const bookmarksTools = new BookmarksApiTools(server, {
  getBookmarks: true,
  createBookmark: true,
});
bookmarksTools.register();
```

--------------------------------

### Register Tool with npm

Source: https://docs.mcp-b.ai/llms.txt

Install the `@mcp-b/global` package via npm and then register a tool using `navigator.modelContext.registerTool()` in your TypeScript code.

```bash
npm install @mcp-b/global
```

```typescript
import '@mcp-b/global';

navigator.modelContext.registerTool({
  name: 'get_weather',
  description: 'Get weather for a city',
  inputSchema: { type: 'object', properties: { city: { type: 'string' } }, required: ['city'] },
  handler: async ({ city }) => ({ content: [{ type: 'text', text: `Weather in ${city}: 72F, sunny` }] })
});
```

--------------------------------

### Get Assistant Conversations

Source: https://docs.mcp-b.ai/llms.txt

Retrieves AI assistant conversation history including queries, responses, cited sources, and categories.

```APIDOC
## Get Assistant Conversations

### Description
Retrieves AI assistant conversation history including queries, responses, cited sources, and categories.

### Method
GET

### Endpoint
/api/analytics/assistant-conversations

### Parameters
#### Query Parameters
- **start_date** (string) - Optional - The start date for filtering conversations.
- **end_date** (string) - Optional - The end date for filtering conversations.
```

--------------------------------

### Initialize WebMCP and Render App

Source: https://docs.mcp-b.ai/tutorials/first-react-tool

The entry point for the application where the WebMCP polyfill is initialized before the React root is rendered.

```tsx
import { initializeWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';
import { StrictMode } from 'react';
import { createRoot } from 'react-dom/client';
import { App } from './App';

initializeWebMCPPolyfill();

createRoot(document.getElementById('root')!).render(

<StrictMode>
  <App />
</StrictMode>
);
```

--------------------------------

### Import useWebMCPContext hook

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Import the convenience wrapper for read-only context tools.

```ts
import { useWebMCPContext } from '@mcp-b/react-webmcp';
```

--------------------------------

### Register an MCP prompt

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Registers a prompt with a name, description, optional argument schema, and a get handler that returns prompt messages.

```ts
const handle = server.registerPrompt({
  name: 'summarize',
  description: 'Summarize a document',
  argsSchema: {
    type: 'object',
    properties: { url: { type: 'string', description: 'Document URL' } },
    required: ['url'],
  },
  async get(args) {
    return {
      messages: [{ role: 'user', content: { type: 'text', text: `Summarize: ${args.url}` } }],
    };
  },
});
```

--------------------------------

### Configure and load WebMCP Polyfill via script tag

Source: https://docs.mcp-b.ai/packages/webmcp-polyfill/reference

Use the window.__webMCPPolyfillOptions object to configure the polyfill before loading the IIFE script.

```html
<script>
  window.__webMCPPolyfillOptions = {
    installTestingShim: 'if-missing',
  };
</script>
<script src="https://unpkg.com/@mcp-b/webmcp-polyfill@latest/dist/index.iife.js"></script>
```

--------------------------------

### Get Agent Job

Source: https://docs.mcp-b.ai/llms.txt

Retrieves the status and details of a specific agent job, including progress, branch info, and pull request details.

```APIDOC
## Get Agent Job

### Description
Retrieves the status and details of a specific agent job, including progress, branch info, and pull request details.

### Method
GET

### Endpoint
/api/agent/get-agent-job/{job_id}

### Parameters
#### Path Parameters
- **job_id** (string) - Required - The ID of the agent job to retrieve.
```

--------------------------------

### Initialize WebMCP Polyfill

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Initialize the polyfill and register a tool using the standard WebMCP interface.

```ts
import { initializeWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';

initializeWebMCPPolyfill();

document.modelContext.registerTool({
  name: 'get-page-title',
  description: 'Get the current page title',
  inputSchema: { type: 'object', properties: {} },
  async execute() {
    return {
      content: [{ type: 'text', text: document.title }],
    };
  },
});
```

--------------------------------

### listPrompts()

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Retrieves metadata for all enabled prompts.

```APIDOC
## listPrompts()

### Description
Returns metadata for all enabled prompts, including argument schemas.
```

--------------------------------

### Initialize in Next.js

Source: https://docs.mcp-b.ai/how-to/frameworks

Import in a Client Component layout rather than the root layout to avoid disabling SSR.

```tsx
'use client';

import '@mcp-b/global';

export default function DashboardLayout({ children }) {
  return <>{children}</>;
}
```

--------------------------------

### List available demo tools

Source: https://docs.mcp-b.ai/tutorials/first-native-preview

Retrieve and log the metadata for tools registered by the current page.

```javascript
const tools = navigator.modelContextTesting.listTools();
console.log(tools);
```

--------------------------------

### Create tool component

Source: https://docs.mcp-b.ai/tutorials/first-react-tool

Implement a component that registers a tool using the useWebMCP hook and displays its execution state.

```tsx
import { useWebMCP } from 'usewebmcp';

const INPUT_SCHEMA = {
  type: 'object',
  properties: {
    name: { type: 'string' },
  },
} as const;

export function App() {
  const helloTool = useWebMCP({
    name: 'say_hello',
    description: 'Returns a hello message',
    inputSchema: INPUT_SCHEMA,
    execute: async (args) => ({
      content: [{ type: 'text', text: `Hello ${args?.name ?? 'world'}!` }],
    }),
  });

  return (
    <div>
      <h1>My First React WebMCP Tool</h1>
      <p>Tool "say_hello" registered.</p>
      <p>Executions: {helloTool.state.executionCount}</p>
      <p>
        Last result:{' '}
        {helloTool.state.lastResult ? JSON.stringify(helloTool.state.lastResult) : 'none'}
      </p>
      {helloTool.state.error && (
        <p style={{ color: 'red' }}>Error: {helloTool.state.error.message}</p>
      )}
      <button onClick={() => helloTool.execute({ name: 'React' })}>Run Tool Locally</button>
    </div>
  );
}
```

--------------------------------

### Import useWebMCP hook

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Import the primary hook for registering tools.

```ts
import { useWebMCP } from '@mcp-b/react-webmcp';
```

--------------------------------

### Implement CounterTool with usewebmcp

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Define a tool using the core usewebmcp hook. Requires document.modelContext to be provided by a polyfill or global provider.

```tsx
import { useWebMCP } from 'usewebmcp';

export function CounterTool() {
  const counterTool = useWebMCP({
    name: 'counter_get',
    description: 'Get current count',
    inputSchema: { type: 'object', properties: {} } as const,
    execute: async () => ({ count: 42 }),
  });

  return (
    <div>
      <p>Executions: {counterTool.state.executionCount}</p>
    </div>
  );
}
```

--------------------------------

### Configure Auto-initialization

Source: https://docs.mcp-b.ai/packages/global/reference

Control the auto-initialization behavior of the global model context using the window.__webModelContextOptions object.

```html
<script>
  window.__webModelContextOptions = {
    autoInitialize: true,
    transport: {
      tabServer: { allowedOrigins: ['https://myapp.com'] },
    },
  };
</script>
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```

```html
<script>
  window.__webModelContextOptions = { autoInitialize: false };
</script>
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
<script>
  MCPB.initializeWebModelContext();
</script>
```

--------------------------------

### Initialize WebMCP polyfill

Source: https://docs.mcp-b.ai/tutorials/first-react-tool

Add the polyfill initialization to the main entry point before rendering the React app.

```tsx
import { initializeWebMCPPolyfill } from '@mcp-b/webmcp-polyfill';
import { StrictMode } from 'react';
import { createRoot } from 'react-dom/client';
import { App } from './App';

initializeWebMCPPolyfill();

createRoot(document.getElementById('root')!).render(
  <StrictMode>
    <App />
  </StrictMode>
);
```

--------------------------------

### Discovering tools via AI agent

Source: https://docs.mcp-b.ai/how-to/use-devtools-mcp

Instruction for the agent to navigate to the development server and discover newly registered tools.

```text
Navigate to http://localhost:3000 and list the available tools
```

--------------------------------

### mcp-iframe-ready

Source: https://docs.mcp-b.ai/packages/mcp-iframe/reference

Fired when the element successfully connects to the iframe's MCP server and registers all tools, resources, and prompts on the parent.

```APIDOC
## Event: mcp-iframe-ready

### Description
Fired when the element connects to the iframe's MCP server and registers all items on the parent.

### Detail Type
- **tools** (string[]) - List of prefixed tool names.
- **resources** (string[]) - List of prefixed resource URIs.
- **prompts** (string[]) - List of prefixed prompt names.
```

--------------------------------

### useWebMCPPrompt(config)

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Registers an MCP prompt on the document model context.

```APIDOC
## useWebMCPPrompt(config)

### Description
Registers an MCP prompt that can be used by AI assistants to generate structured messages.

### Parameters
- **name** (string) - Required - Prompt identifier
- **description** (string) - Optional - Human-readable description
- **argsSchema** (JSON Schema/Standard Schema v1/Zod v3) - Optional - Argument schema
- **get** (function) - Required - Message generator: (args) => { messages: PromptMessage[] }
```

--------------------------------

### useWebMCP(config, deps?)

Source: https://docs.mcp-b.ai/packages/usewebmcp/reference

The primary hook for registering tools with the model context. It accepts a configuration object and an optional dependency array, returning state and control methods.

```APIDOC
## useWebMCP(config, deps?)

### Description
Registers tools with `document.modelContext` on mount and unregisters them on unmount. Requires `document.modelContext` to be available at runtime.

### Parameters
- **config** (WebMCPConfig) - Required - Tool configuration object.
- **deps** (DependencyList) - Optional - Dependency array that triggers tool re-registration when values change.

### Returns
- **state** (ToolExecutionState) - Current execution state.
- **execute(input)** ((input) => Promise) - Manually invoke the tool from your UI or tests.
- **reset()** (() => void) - Reset state to initial values.
```

--------------------------------

### initializeWebModelContext

Source: https://docs.mcp-b.ai/packages/global/reference

Initializes the WebModelContext with specific transport configurations and behavior settings.

```APIDOC
## initializeWebModelContext

### Description
Initializes the WebModelContext. Users can configure the transport layer, auto-initialization behavior, and native model context handling.

### Parameters
#### Options (WebModelContextInitOptions)
- **transport** (TransportConfiguration) - Optional - Transport layer configuration.
- **autoInitialize** (boolean) - Optional - Whether to auto-initialize on import (Default: true).
- **nativeModelContextBehavior** ('preserve' | 'patch') - Optional - How to handle an existing native modelContext (Default: 'preserve').
- **installTestingShim** (boolean | 'always' | 'if-missing') - Optional - Controls navigator.modelContextTesting installation (Default: 'if-missing').

### TransportConfiguration
- **tabServer** (Partial<TabServerTransportOptions> | false) - Optional - Tab transport options, or false to disable.
- **iframeServer** (Partial<IframeChildTransportOptions> | false) - Optional - Iframe transport options, or false to disable.

### Usage Example
```ts
// Restrict to specific origins
initializeWebModelContext({
  transport: {
    tabServer: { allowedOrigins: ['https://myapp.com'] },
  },
});

// Disable tab transport (iframe only)
initializeWebModelContext({
  transport: { tabServer: false },
});
```
```

--------------------------------

### Launch Chromium with native API flags

Source: https://docs.mcp-b.ai/how-to/test-native-and-polyfill

Use these flags when running Chromium in headless CI environments to enable experimental features.

```bash
chromium \
  --headless=new \
  --enable-experimental-web-platform-features \
  --enable-features=WebMCPTesting,DevToolsWebMCPSupport \
  --disable-gpu \
  --no-sandbox
```

--------------------------------

### Initialize Web Model Context

Source: https://docs.mcp-b.ai/packages/global/reference

Manually initialize the global adapter with specific transport options.

```ts
import { initializeWebModelContext } from '@mcp-b/global';

initializeWebModelContext({
  transport: {
    tabServer: { allowedOrigins: ['https://example.com'] },
  },
});
```

--------------------------------

### Registering a Resource

Source: https://docs.mcp-b.ai/how-to/register-prompts-and-resources

Import the global module and use document.modelContext.registerResource to expose data to AI clients.

```typescript
import '@mcp-b/global';
```

```typescript
const { unregister } = document.modelContext.registerResource({
  uri: 'app://config',
  name: 'App Configuration',
  description: 'Current application configuration',
  mimeType: 'application/json',
  read: async () => ({
    contents: [{ uri: 'app://config', text: JSON.stringify(appConfig) }]
  })
});
```

```typescript
unregister();
```

--------------------------------

### useWebMCP(options)

Source: https://docs.mcp-b.ai/packages/usewebmcp/reference

Registers an MCP tool with the provided configuration. The hook handles tool execution, state management, and schema validation.

```APIDOC
## useWebMCP(options)

### Description
Registers an MCP tool. The hook manages the tool's lifecycle, including registration, execution, and state tracking.

### Parameters
- **name** (string) - Required - The name of the tool.
- **description** (string) - Required - A description of the tool's purpose.
- **outputSchema** (JSON Schema) - Optional - Schema for validating and inferring the output type.
- **execute** (function) - Required - The function to execute when the tool is called.

### Usage Example
```tsx
const OUTPUT_SCHEMA = {
  type: 'object',
  properties: {
    total: { type: 'integer' },
  },
  required: ['total'],
  additionalProperties: false,
} as const;

const tool = useWebMCP({
  name: 'count_items',
  description: 'Count items',
  outputSchema: OUTPUT_SCHEMA,
  execute: () => ({ total: 3 }),
});
```
```

--------------------------------

### Register existing tools with backfillTools

Source: https://docs.mcp-b.ai/packages/webmcp-ts-sdk/reference

Use this method to register tools already present on a native or polyfill context. It skips tools that are already registered on the server.

```ts
const synced = server.backfillTools(existingTools, async (name, args) => {
  const tool = (await existingContext.getTools()).find((item) => item.name === name);
  if (!tool) throw new Error(`Tool not found: ${name}`);

  const resultJson = await existingContext.executeTool(tool, JSON.stringify(args));
  return resultJson === null ? { content: [] } : JSON.parse(resultJson);
});
```

--------------------------------

### useWebMCP(config, deps?)

Source: https://docs.mcp-b.ai/packages/react-webmcp/reference

Registers a tool with the MCP-B runtime. It supports Zod schemas and Standard Schema v1 for input/output validation.

```APIDOC
## useWebMCP(config, deps?)

### Description
Registers a tool with the MCP-B runtime. The handler function is executed when the tool is invoked by an AI assistant.

### Parameters
- **name** (string) - Required - Unique tool identifier
- **description** (string) - Required - Human-readable description
- **inputSchema** (JSON Schema/Standard Schema v1/Zod v3) - Optional - Input parameters schema
- **outputSchema** (JSON Schema/Standard Schema v1/Zod v3) - Optional - MCP-B output helper metadata
- **annotations** (ToolAnnotations) - Optional - Metadata hints
- **handler** (function) - Required - Tool implementation function: (input) => T | Promise<T>
- **onSuccess** (function) - Optional - Success callback: (result, input) => void
- **onError** (function) - Optional - Error callback: (error, input) => void
```

--------------------------------

### Configure MCP-B Runtime Options

Source: https://docs.mcp-b.ai/how-to/choose-runtime

Set global options before loading the IIFE script to customize runtime behavior.

```html
<script>
  window.__webModelContextOptions = {
    transport: {
      tabServer: { allowedOrigins: ['https://myapp.com'] },
    },
  };
</script>
<script src="https://unpkg.com/@mcp-b/global@latest/dist/index.iife.js"></script>
```
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